Analysis of the efficacy of a nanoparticle combining antibiotics and enzymes to control peri-implant infections

• Grant number: 24/14595-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2024
• End date: November 30, 2025
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Caroline Dini
• Grantee: Ana Gabriela Campeon Borghesi
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Peri-implant infections in dental implants are a recurring and significant challenge in current implant dentistry due to the complexity of the factors involved, including the presence of dysbiotic pathogenic biofilm and the difficult-to-access site of these infections, which makes treatment difficult. In addition, the biofilm's extracellular matrix ensures structure, access to nutrients and adhesion of microorganisms, making it difficult for antimicrobial drugs to reach and be effective. As a result, although various therapies have been proposed for the treatment of peri-implant infections, there is still a challenge in re-establishing a state of health in sites with peri-implant infections. Therefore, with the aim of combining a therapy for the degradation of the extracellular matrix of the peri-implant biofilm and using an antibiotic targeted at the pathogenic microorganisms present in these infections, this study aims to evaluate the antimicrobial potential of chitosan-g-poly(N-vinylcaprolactam) nanoparticles carrying an extracellular matrix DNA degrading agent (DNase) and the antibiotic metronidazole (MTZ), which are being developed by the person responsible for this proposal in her postdoctoral project (Fapesp Process #23/02180-8). Firstly, the cytotoxicity of the NPs will be evaluated in contact with human gingival fibroblasts and human gingival keratinocytes from oral mucosa. Subsequently, in this Scientific Initiation proposal, the antimicrobial potential of the NPs will be evaluated in monospecies biofilms of Porphyromonas gingivalis and in multispecies biofilms (using a microcosm model with supragingival and subgingival phases).For this purpose, in the in vitro microbiological tests, the mono- and multispecies biofilms will be evaluated in terms of colony-forming units (CFU), dry weight, microbial composition by DNA-DNA checkerboard, quantity of exopolysaccharides, extracellular DNA dosage, as well as the evaluation of structural organization by scanning electron microscopy and the presence of live and dead cells, as well as the matrix, by laser confocal microscopy.The quantitative data will be subjected to appropriate statistical analysis with a significance level of 5%.